Please add a "manual add channel" feature.
I live in San Jose, CA (population 1 million). In order to get NBC and watch the Olympics, we all have to point our antenna's at San Francisco which is the foggiest city on planet. Since water absorbs the TV signal, in the morning I have crappy reception and in the evening it is fine. Its a pain to have to rescan at the right times just to get the stations I want.
I understand why you may want to limit customers to stations that only have clear signal for the best experience, but its just not the nature of OTA. Perhaps make this an "advanced" mode but major cities all have to deal with some level of flaky reception. We understand what we are getting into and don't enjoy fighting against the UI which prevents this.